Business transactions are increasingly taking place over the Internet and other electronic communication networks. Electronic markets may provide a forum for such transactions, allowing buyers to locate sellers, and vice versa. This process may involve a buyer (or seller) identifying a seller (or buyer) offering to sell (or buy) a suitable quantity of a particular item at a suitable price. Typically, the buyer wants to buy at the lowest possible price, and the seller wants to sell at the highest possible price. It may be advantageous for a buyer (or seller) to monitor market conditions and buy (or sell) when such conditions meet certain criteria favorable to the buyer (or seller). However, market conditions may be subject to constant change, and such changes may occur rapidly. It may therefore be difficult for a buyer (or seller) to monitor market conditions and make buy (or sell) decisions based on market conditions meeting certain criteria. Additionally, a buyer (or seller) may only want to buy from (or sell to) certain sellers (or buyers) participating in the market, which may limit options available to the buyer (or seller) and make it more difficult to determine whether market conditions are favorable.